The array of brilliant stars of the winter sky: Sirius (8.7 LY), Procyon (10.4 LY) Pollux, Castor, Capella, Aldebaran, Betelgeuse, and Rigel are all members of our own spiral arm. We live on its inner edge, and thus when we turn our back to the center of the galaxy and look to the anti-center we see these bright stars of winter. Sagittarius and Scorpius are in the direction of the center of the galaxy and lie in the summer skies.
Hydra: the longest constellation in the sky, it covers approximately of the heavens. Brightest star is Alphard, the lonely one. It is associated with Crater and Corvus.
Heading directly south from Corvus we get to the Southern Cross and then on to the south pole.
To the left of the Southern Cross is alpha and beta Centauri. Alpha Centauri is our nearest stellar neighbor at a distance of 4.3 LY; it has a brightness similar to that of the sun. Beta Centauri has a luminosity 1500 times that of the sun and a distance of 190 LY.
Virgo: Brightest star is Spica which one can locate by the pointer stars of Corvus, or by arching from the handle of the big dipper, through Arcturus, and then on to Spica. North of Virgo is the Realm of the Galaxies because it is in the direction of the pole of the galaxy, and therefore is the place where we can see deepest into space. In that area is Coma Berenices and Canis Venatici (the hunting dogs). The pole of the Milky Way galaxy lies in the middle of Coma Berenices. A glorious sight in a dark sky is the arch of the milky way draped over Coma Berenices
The Virgins diamond is made up by Spica, Arcturus, alpha Canes Venatici, and Denebola.
Arcturus is the brightest star in Bootes, the great gourmet ice cream cone in the sky. (I think the scoop is Rocky Road)
To the west of Virgo is Libra, the constellation I have learned to hate the most. It used to be the claws of a very fine Scorpion. The northern two of the brightest stars of Libra is beta Libra and is known in Arabic as Zubeneschamali, the northern claw. Below that is alpha Libra which is Zubenelgenubi, the southern claw.
The red heart of the Scorpion is Antares, "opposite Mars". It is a red supergiant similar to Betelgeuse, with a diameter 300 times that of the sun and a distance of 300 LY.
Beyond Scorpius is Sagittarius, the Great Tea Pot in the sky, and then we come Capricorn and Aquarius. Below Aquarius is one of the four Royal Stars of antiquity, Fomalhaut which marked the position of the sun near winter solstice (the others were Aldebaran, Regulus, & Antares) Fomalhaut is in the southern fish, Piscis Austrinus. Next along the ecliptic is Pisces, consisting of the southern and northern fist. Currently, at Vernal Equinox, the sun is in the southern fish. Above Pisces is the Great Square of Pegasus, which is also the great baseball diamond in the sky. Along the line from home plate to first base is Andromeda, which contains the Andromeda galaxy, our sister spiral galaxy, at a distance of 2 million light years.
After Pisces is Aires and then Taurus, in which we encounter the Pleades.
We determined the modern dates for sun birth signs. For example on the eve of the 21st century, the sun lies in Aires between April 20 and May 10. The longest sun sign is Pisces which lasts from March 1 to April 20; the shortest is Cancer which lasts from July 21 to August 10. Now is the time for all of your to change your personalities based upon your correct sun signs!
We continued our discussion from last Tuesday about time slowing down and changing the color of light. One of the astonishing results of Einsteins special theory of relativity is that clocks slow when they are moving relative to an observer. The result is a red shift of the light produced in that slowed time. Such a red shift becomes infinite when the source of light is moving at the speed of light, when time has stopped. The distant galaxies of our universe which have red shifts due to their Doppler effect are thus double red shifted due to the slowing down of their own time. The combination of these two red shifts is the Relativistic Doppler effect, discussed in SNOW Appendix 14. Thus a red shift of 4, which is impossible in the simple Doppler effect, since it would require v/c = 4, is produced by a galaxy moving at a speed of .923c.
The most extreme red shift that we know in the universe is produced by the primordial fireball radiation, with a temperature of 2.71K and a red shift of 1500. It is moving outward from us a nearly the speed of light and was produced when the universe was only about 500,000 years old. That radiation was initially generated when the antimatter and matter of the early universe annihilated each other in a super colossal fireball. All of that matter and antimatter was destroyed in a great flash of light. Left in that explosion was a very tiny residual of matter, which is us and our redwood trees, whales, and cats. This is one of the truly GREAT MYSTERIES of the universe: why there is any matter at all!
Our is almost entirely a universe of light in which photons of very ancient light totally dominate: for every particle of matter there are a billion particle of matter. Matter is a negligible flotsam floating in a sea of light.